Multiple message types and procedure for selection of a message type for a random access message in a two-step random access procedure

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may determine a message type for a random access message associated with a two-step random access channel procedure. The message type may be either a first message type or a second message type that is different from the second message type. The message type may be determined based at least in part on whether a signal strength satisfies a signal strength threshold. The user equipment may transmit the random access message based at least in part on the determined message type. Numerous other aspects are provided.

CROSS-REFERENCE TO RELATED APPLICATION

This Patent Application claims priority to U.S. Provisional PatentApplication No. 62/968,907, filed on Jan. 31, 2020, entitled “MULTIPLEMESSAGE TYPES AND PROCEDURE FOR SELECTION OF A MESSAGE TYPE FOR A RANDOMACCESS MESSAGE IN A TWO-STEP RANDOM ACCESS PROCEDURE,” and assigned tothe assignee hereof. The disclosure of the prior Application isconsidered part of and is incorporated by reference into this PatentApplication.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication and to techniques and apparatuses for multiple messagetypes and a procedure for selection of a message type for a randomaccess message in a two-step random access procedure.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A user equipment (UE) may communicate with a base station (BS)via the downlink and uplink. The downlink (or forward link) refers tothe communication link from the BS to the UE, and the uplink (or reverselink) refers to the communication link from the UE to the BS. As will bedescribed in more detail herein, a BS may be referred to as a Node B, agNB, an access point (AP), a radio head, a transmit receive point (TRP),a New Radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. New Radio (NR), which may also bereferred to as 5G, is a set of enhancements to the LTE mobile standardpromulgated by the Third Generation Partnership Project (3GPP). NR isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingorthogonal frequency division multiplexing (OFDM) with a cyclic prefix(CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g.,also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) onthe uplink (UL), as well as supporting beamforming, multiple-inputmultiple-output (MIMO) antenna technology, and carrier aggregation.However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in LTE and NRtechnologies. Preferably, these improvements should be applicable toother multiple access technologies and the telecommunication standardsthat employ these technologies.

SUMMARY

In some aspects, a method of wireless communication, performed by a UE,may include determining a message type for a random access messageassociated with a two-step random access channel (RACH) procedure,wherein the message type is either a first message type or a secondmessage type, the first message type being different from the secondmessage type, and wherein the message type is determined based at leastin part on whether a signal strength satisfies a signal strengththreshold; and transmitting the random access message based at least inpart on the determined message type.

In some aspects, a method of wireless communication, performed by a basestation, may include receiving, from a UE, a random access messageassociated with a two-step RACH procedure; determining, based at leastin part on the random access message, a message type of the randomaccess message, wherein the message type is either a first message typeor a second message type, the first message type being different fromthe second message type; and processing the random access message basedat least in part on determining the message type of the random accessmessage.

In some aspects, a UE for wireless communication may include a memoryand one or more processors operatively coupled to the memory. The memoryand the one or more processors may be configured to determine a messagetype for a random access message associated with a two-step RACHprocedure, wherein the message type is either a first message type or asecond message type, the first message type being different from thesecond message type, and wherein the message type is determined based atleast in part on whether a signal strength satisfies a signal strengththreshold; and transmit the random access message based at least in parton the determined message type.

In some aspects, a base station for wireless communication may include amemory and one or more processors operatively coupled to the memory. Thememory and the one or more processors may be configured to receive, froma UE, a random access message associated with a two-step RACH procedure;determine, based at least in part on the random access message, amessage type of the random access message, wherein the message type iseither a first message type or a second message type, the first messagetype being different from the second message type; and process therandom access message based at least in part on determining the messagetype of the random access message.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a UE, may causethe one or more processors to determine a message type for a randomaccess message associated with a two-step RACH procedure, wherein themessage type is either a first message type or a second message type,the first message type being different from the second message type, andwherein the message type is determined based at least in part on whethera signal strength satisfies a signal strength threshold; and transmitthe random access message based at least in part on the determinedmessage type.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a base station,may cause the one or more processors to receive, from a UE, a randomaccess message associated with a two-step RACH procedure; determine,based at least in part on the random access message, a message type ofthe random access message, wherein the message type is either a firstmessage type or a second message type, the first message type beingdifferent from the second message type; and process the random accessmessage based at least in part on determining the message type of therandom access message.

In some aspects, an apparatus for wireless communication may includemeans for determining a message type for a random access messageassociated with a two-step RACH procedure, wherein the message type iseither a first message type or a second message type, the first messagetype being different from the second message type, and wherein themessage type is determined based at least in part on whether a signalstrength satisfies a signal strength threshold; and means fortransmitting the random access message based at least in part on thedetermined message type.

In some aspects, an apparatus for wireless communication may includemeans for receiving, from a UE, a random access message associated witha two-step RACH procedure; means for determining, based at least in parton the random access message, a message type of the random accessmessage, wherein the message type is either a first message type or asecond message type, the first message type being different from thesecond message type; and means for processing the random access messagebased at least in part on determining the message type of the randomaccess message.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment, basestation, wireless communication device, and/or processing system assubstantially described herein with reference to and as illustrated bythe drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purposesof illustration and description, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can beunderstood in detail, a more particular description, briefly summarizedabove, may be had by reference to aspects, some of which are illustratedin the appended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain typical aspects of this disclosure andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects. The samereference numbers in different drawings may identify the same or similarelements.

FIG. 1 is a block diagram conceptually illustrating an example of awireless communication network, in accordance with various aspects ofthe present disclosure.

FIG. 2 is a block diagram conceptually illustrating an example of a basestation in communication with a UE in a wireless communication network,in accordance with various aspects of the present disclosure.

FIG. 3 is a diagram illustrating an example of selection of a messagetype for a random access message in a two-step RACH procedure, inaccordance with various aspects of the present disclosure.

FIG. 4 is a diagram illustrating an example process performed, forexample, by a user equipment, in accordance with various aspects of thepresent disclosure.

FIG. 5 is a diagram illustrating an example process performed, forexample, by a base station, in accordance with various aspects of thepresent disclosure.

FIG. 6 is a conceptual data flow diagram illustrating an example of adata flow between different components in an example apparatus.

FIG. 7 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

FIG. 8 is a conceptual data flow diagram illustrating an example of adata flow between different components in an example apparatus.

FIG. 9 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, and/or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It should be noted that while aspects may be described herein usingterminology commonly associated with 3G and/or 4G wireless technologies,aspects of the present disclosure can be applied in othergeneration-based communication systems, such as 5G and later, includingNR technologies.

FIG. 1 is a diagram illustrating a wireless network 100 in which aspectsof the present disclosure may be practiced. The wireless network 100 maybe an LTE network or some other wireless network, such as a 5G or NRnetwork. The wireless network 100 may include a number of BSs 110 (shownas BS 110 a, BS 110 b, BS 110 c, and BS 110 d) and other networkentities. ABS is an entity that communicates with user equipment (UEs)and may also be referred to as a base station, a NR BS, a Node B, a gNB,a 5G node B (NB), an access point, a transmit receive point (TRP),and/or the like. Each BS may provide communication coverage for aparticular geographic area. In 3GPP, the term “cell” can refer to acoverage area of a BS and/or a BS subsystem serving this coverage area,depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). ABS for a macro cell may bereferred to as a macro BS. ABS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1, a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in thewireless network 100 through various types of backhaul interfaces suchas a direct physical connection, a virtual network, and/or the likeusing any suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1, a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impacts on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, sensors, meters,monitors, location tags, and/or the like, that may communicate with abase station, another device (e.g., remote device), or some otherentity. A wireless node may provide, for example, connectivity for or toa network (e.g., a wide area network such as Internet or a cellularnetwork) via a wired or wireless communication link. Some UEs may beconsidered Internet-of-Things (IoT) devices, and/or may be implementedas NB-IoT (narrowband internet of things) devices. Some UEs may beconsidered a Customer Premises Equipment (CPE). UE 120 may be includedinside a housing that houses components of UE 120, such as processorcomponents, memory components, and/or the like.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,and/or the like. A frequency may also be referred to as a carrier, afrequency channel, and/or the like. Each frequency may support a singleRAT in a given geographic area in order to avoid interference betweenwireless networks of different RATs. In some cases, NR or 5G RATnetworks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure(V2I) protocol, and/or the like), a mesh network, and/or the like. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

In some aspects, a UE 120 and/or a base station 110 may perform one ormore operations associated with selecting a message type, of multiplemessage types, for a random access message in a two-step random accessprocedure. For example, the UE 120 may determine a message type for arandom access message associated with the two-step RACH procedure, asdescribed herein. In some aspects, the message type may be either afirst message type (e.g., msgA) or a second message type (e.g., acoverage enhanced msgA), and the UE 120 may determine the message typebased at least in part on whether a signal strength satisfies athreshold. After determining the message type, the UE 120 may transmitthe random access message accordingly. In some aspects, a base station110 may receive the random access message associated with the two-stepRACH procedure, determine the message type, and process the randomaccess message accordingly, as described herein. In this way, benefitsprovided by the two-step RACH procedure (e.g., reduction in signalingoverhead and/or latency, improvement in RACH capacity and/or powerefficiency) can be realized, while coverage of the random access messagemay be increased.

As indicated above, FIG. 1 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 1.

FIG. 2 shows a block diagram of a design 200 of base station 110 and UE120, which may be one of the base stations and one of the UEs in FIG. 1.Base station 110 may be equipped with T antennas 234 a through 234 t,and UE 120 may be equipped with R antennas 252 a through 252 r, where ingeneral T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI) and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., the cell-specific reference signal (CRS)) and synchronizationsignals (e.g., the primary synchronization signal (PSS) and secondarysynchronization signal (SSS)). A transmit (TX) multiple-inputmultiple-output (MIMO) processor 230 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, the overheadsymbols, and/or the reference symbols, if applicable, and may provide Toutput symbol streams to T modulators (MODs) 232 a through 232 t. Eachmodulator 232 may process a respective output symbol stream (e.g., forOFDM and/or the like) to obtain an output sample stream. Each modulator232 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 232 a through 232 t may be transmittedvia T antennas 234 a through 234 t, respectively. According to variousaspects described in more detail below, the synchronization signals canbe generated with location encoding to convey additional information.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 256may obtain received symbols from all R demodulators 254 a through 254 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. A channel processormay determine reference signal received power (RSRP), received signalstrength indicator (RSSI), reference signal received quality (RSRQ),channel quality indicator (CQI), and/or the like. In some aspects, oneor more components of UE 120 may be included in a housing.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 110. At base station 110, the uplink signals from UE 120 andother UEs may be received by antennas 234, processed by demodulators232, detected by a MIMO detector 236 if applicable, and furtherprocessed by a receive processor 238 to obtain decoded data and controlinformation sent by UE 120. Receive processor 238 may provide thedecoded data to a data sink 239 and the decoded control information tocontroller/processor 240. Base station 110 may include communicationunit 244 and communicate to network controller 130 via communicationunit 244. Network controller 130 may include communication unit 294,controller/processor 290, and memory 292.

Controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform one ormore techniques associated with multiple message types and a procedurefor selection of a message type for a random access message in atwo-step random access procedure, as described in more detail elsewhereherein. For example, controller/processor 240 of base station 110,controller/processor 280 of UE 120, and/or any other component(s) ofFIG. 2 may perform or direct operations of, for example, process 4 ofFIG. 4 and/or other processes as described herein. Memories 242 and 282may store data and program codes for base station 110 and UE 120,respectively. In some aspects, memory 242 and/or memory 282 may comprisea non-transitory computer-readable medium storing one or moreinstructions for wireless communication. For example, the one or moreinstructions, when executed by one or more processors of the basestation 110 and/or the UE 120, may perform or direct operations of, forexample, process 400 of FIG. 4 and/or other processes as describedherein. A scheduler 246 may schedule UEs for data transmission on thedownlink and/or uplink.

In some aspects, UE 120 may include means for determining a message typefor a random access message associated with a two-step RACH procedure,wherein the message type is either a first message type or a secondmessage type, the first message type being different from the secondmessage type, and wherein the message type is determined based at leastin part on whether a signal strength satisfies a signal strengththreshold; means for transmitting the random access message based atleast in part on the determined message type; and/or the like. In someaspects, such means may include one or more components of UE 120described in connection with FIG. 2, such as controller/processor 280,transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252,DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

In some aspects, base station 110 may include means for receiving, froma UE 120, a random access message associated with a two-step RACHprocedure; means for determining, based at least in part on the randomaccess message, a message type of the random access message, wherein themessage type is either a first message type or a second message type,the first message type being different from the second message type;means for processing the random access message based at least in part ondetermining the message type of the random access message; and/or thelike. In some aspects, such means may include one or more components ofbase station 110 described in connection with FIG. 2, such as antenna234, DEMOD 232, MIMO detector 236, receive processor 238,controller/processor 240, transmit processor 220, TX MIMO processor 230,MOD 232, antenna 234, and/or the like.

As indicated above, FIG. 2 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 2.

A two-step RACH procedure includes two steps (rather than four steps, asin a traditional four-step RACH procedure). The two-step RACH procedurecan, in some cases, provide a reduction in signaling overhead and/orlatency, and can provide improvement in RACH capacity and/or powerefficiency. In the two-step RACH procedure, a UE transmits a randomaccess message (referred to as msgA) that includes a preamble and apayload (e.g., a physical uplink shared channel (PUSCH) payload) of aconfigurable size (e.g., from a few bytes to a few hundred bytes). Thepreamble may assist with a timing offset estimation performed by a basestation. In general, the UE transmits the preamble and then transmitsthe payload after a configurable amount of time (e.g., including a guardperiod and/or a transmission gap). Here, the configurable amount of timemay serve to mitigate interference (e.g., inter-symbol interference(ISI), inter-carrier interference (ICI), and/or the like). The preambleand the payload can be transmitted in the same slot or in differentslots.

Multiple UEs performing the two-step RACH procedure can share a samePUSCH occasion. That is, multiple UEs performing the two-step RACHprocedure can share a same set of resources for transmitting randomaccess message payloads. Such sharing may occur when, for example, therandom access messages of the multiple UEs use similar modulation andcoding schemes (MCSs), similar waveforms, or similar payload sizes.Resource allocation for a given PUSCH occasion can be specified relativeto a RACH occasion (e.g., a set of resources for transmitting randomaccess message preambles), for example, by semi-statically ordynamically configured offsets in time and/or frequency. Both separateand shared RACH occasions can be configured for two-step RACH. Further,when a RACH occasion is shared between a two-step RACH procedure and afour-step RACH procedure, a pool of preambles can be partitioned intomutually exclusive subsets, each of which is associated with a differenttype of RACH procedure.

A base station may receive the random access message associated with thetwo-step RACH procedure, and may detect the preamble and decode thepayload. The base station may then transmit a random access response(referred to as msgB) to the UE. The random access response includes aphysical downlink control channel (PDCCH) communication and a physicaldownlink shared channel (PDSCH) payload. Here, the PDCCH communicationidentifies a set of resources of the PDSCH payload that carriesinformation for the UE. The PDSCH payload can include, for example,contention resolution information for the UE, a cell radio networktemporary identifier (C-RNTI) for the UE, a timing advance (TA) commandfor the UE, and/or the like.

As described above, the aim of the two-step RACH procedure is to providea reduction in signaling overhead and/or latency, and an improvement inRACH capacity and/or power efficiency (e.g., as compared to thefour-step RACH procedure). It is therefore desirable to enable increasedcoverage of the random access message of the two-step RACH procedure(e.g., to allow the two-step RACH procedure to be used, while achievingacceptable coverage). In some cases, coverage enhancement for the randomaccess message of the two-step RACH procedure can be provided bysupporting used of different message types for the random accessmessage.

Some techniques and apparatuses described herein provide techniques andapparatuses for selection of a message type for a random access messagein a two-step RACH procedure. In some aspects, a UE may determine themessage type for the random access message associated with the two-stepRACH procedure, where the message type is either a first message type(e.g., msgA) or a second message type (e.g., a coverage enhanced msgA).In some aspects, the UE may determine the message type based at least inpart on whether a signal strength satisfies a signal strength threshold.In this way, the above-described benefits of the two-step RACH procedurecan be realized, while coverage of the random access message may beincreased. Additional details are described below.

FIG. 3 is a diagram illustrating an example 300 of selection of amessage type for a random access message in a two-step RACH procedure,in accordance with various aspects of the present disclosure.

As shown in FIG. 3 by reference 305, a base station (e.g., base station110) may transmit a synchronization signal block (SSB) (e.g., usingtransmit processor 220, controller/processor 240, memory 242,transmission component 810, and/or the like). In some aspects, the SSBmay include one or more synchronization signals and a physical broadcastchannel (PBCH), as described below. In general, in association withtransmitting a set of SSBs, the base station defines candidate positionsfor SSBs to be transmitted within a radio frame, and the quantity ofcandidate positions corresponds to a quantity of beams radiated in agiven direction. Here, each SSB transmitted by the base station may beassociated with a respective SSB index. As further indicated byreference 305, a UE (e.g., UE 120) may receive (e.g., using receiveprocessor 258, controller/processor 280, memory 282, reception component604, and/or the like) an SSB transmitted by the base station.

As shown by reference 310, the UE may determine (e.g., using receiveprocessor 258, controller/processor 280, memory 282, determinationcomponent 606, and/or the like) a signal strength based at least in parton a reference signal received power (RSRP) associated with the SSB. Insome aspects, the UE may measure a signal strength of a reference signal(e.g., a demodulation reference signal (DMRS)) of each SSB detected bythe UE (e.g., within a particular period of time, such as a period ofone SSB set) and, based on results of these measurements, may identifyan SSB for which the reference signal has a suitable (e.g., strongest)signal strength. Here, the SSB with the suitable signal strength uses asuitable (e.g., best) beam for the UE.

In some aspects, after identifying the suitable beam, the UE may thendecode the PBCH associated with the SSB. The PBCH may carry, forexample, system information (e.g., a master information block (MIB), oneor more system information blocks (SIBs), and/or the like), aconfiguration for remaining minimum system information (RMSI), and oneor more other items of information. Here, decoding the PBCH enables theUE to receive a subsequent physical downlink control channel (PDCCH) anda physical downlink shared channel (PDSCH) that schedule and carry,respectively, RMSI and other system information (OSI). In some aspects,the configuration of the PDCCH for the RMSI may be determined from thePBCH, and a control resource set (CORESET) configuration for the RMSImay be determined based at least in part on an SSB index of the SSB.

In some aspects, the UE may determine, based at least in part on thesignal strength, that the UE is to use a two-step RACH procedure inassociation with accessing the wireless communication system. In someaspects, the UE may determine that the UE is to use the two-step RACHprocedure based at least in part on a signal strength thresholdassociated with identifying a RACH procedure (herein referred to asthreshold Th2). For example, the UE may determine the signal strengthbased at least in part on the RSRP associated with the SSB, as describedabove. The UE may then compare the signal strength to the threshold Th2.Here, if the signal strength satisfies the threshold Th2 (e.g., when thesignal strength is greater than or equal to the threshold Th2), then theUE may determine that the UE is to use the two-step RACH procedure.Conversely, if the signal strength does not satisfy the threshold Th2(e.g., when the signal strength is less than the threshold Th2), thenthe UE may determine that the UE is to use a four-step RACH procedure.For the purposes of the example shown in FIG. 3, the UE has determinedthat the UE is to use the two-step RACH procedure (i.e., that the signalstrength satisfies threshold Th2).

As indicated by reference 315, the UE may determine (e.g., using receiveprocessor 258, transmit processor 264, controller/processor 280, memory282, determination component 606, and/or the like) a message type for arandom access message associated with the two-step RACH procedure. Insome aspects, the message type may be either a first message type or asecond message type. In some aspects, the first message type may be amessage type of a first message in the two-step RACH procedure (e.g.,msgA) and the second message type may be a coverage enhanced messagetype of the first message in the two-step RACH procedure (e.g., acoverage enhanced msgA).

In some aspects, the UE may determine the message type based at least inpart on whether the signal strength satisfies a signal strengththreshold associated with identifying a message type of a random accessmessage for a two-step RACH procedure (herein referred to thresholdTh1). In some aspects, the threshold TH1 may be greater than thethreshold Th2 described above. As an example, the UE may determine thesignal strength based at least in part on the RSRP associated with theSSB, as described above. The UE may then compare the signal strength tothe threshold TH1. Here, if the signal strength satisfies the thresholdTh1 (e.g., when the signal strength is greater than or equal to thethreshold Th1), then the UE may determine that the UE is to use thefirst message type (e.g., msgA) for the random access message of thetwo-step RACH procedure. Conversely, if the signal strength does notsatisfy the threshold Th1 (e.g., when the signal strength is less thanthe threshold Th1), then the UE may determine that the UE is to thesecond message type (e.g., coverage enhanced msgA) for the random accessmessage of the two-step RACH procedure. In some aspects, the thresholdTH1 may be identified in system information (e.g., RMSI) received by theUE from the base station in the manner described above. Thus, in someimplementations, the threshold TH1 (and also the threshold Th2) may beconfigured on the UE by the base station.

In some aspects, one or more characteristics of the first message typemay be different from one or more characteristics of the second messagetype. For example, a physical random access channel (PRACH) formatassociated with the first message type may be different from a PRACHformat associated with the second message type. As another example,PUSCH repetition (i.e., repetition of the PUSCH payload within msgA) maynot be applied for the first message type, and PUSCH repetition may beapplied for the second message type. As another example, an MCSassociated with the first message type may be different from an MCSassociated with the second message type. As another example, a payloadsize associated with the first message type may be different from apayload size associated with the second message type. As anotherexample, a PUSCH resource allocation associated with the first messagetype may be different from a PUSCH resource allocation size associatedwith the second message type. As another example, preamble repetition(i.e., repetition of the preamble of msgA) may not be applied for thefirst message type, and preamble repetition may be applied for thesecond message type. As another example, a length of a preamble for thefirst message type may be less than a length of a preamble for thesecond message type. In some aspects, the one or more characteristics ofthe second message type may be selected or designed so as to providecoverage enhancement as compared to the first message type. That is, theone or more characteristics of the second message type may enable arandom access message of the second message type to be a coverageenhanced random access message for the two-step RACH procedure.

In some aspects, the UE may receive configuration information associatedwith the second message type. The configuration information may includeinformation associated with one or more of the above-describedcharacteristics. For example, the configuration information associatedwith the second message type may include information associated with aPRACH format for the second message type, application of PUSCHrepetition for the second message type, an MCS for the second messagetype, a payload size for the second message type, a resource allocationof a PUSCH for the second message type, application of preamblerepetition for the second message type, a length of a preamble for thesecond message type, and/or the like. In some aspects, the configurationinformation may be transmitted by the base station, and received by theUE, in the SSB, the system information, the PDCCH, the RMSI, and/orlike.

As shown by reference 320, the UE may transmit (e.g., using transmitprocessor 264, controller/processor 280, memory 282, transmissioncomponent 608, and/or the like) the random access message, associatedwith the two-step RACH procedure, based at least in part on thedetermined message type. For example, the UE may transmit the randomaccess message using the first message type when the UE determines thatthe first message type is to be used for the random access message ofthe two-step RACH procedure. Alternatively, the UE may transmit therandom access message using the second message type (e.g., based atleast in part on the configuration associated with the second messagetype) when the UE determines that the second message type is to be usedfor the random access message of the two-step RACH procedure.

In some aspects, a preamble sequence included in the random accessmessage may indicate whether PUSCH repetition was applied whentransmitting the random access message. In such a case, the preamblesequence may be one of a set of preamble sequences associated withindicating application of PUSCH repetition. Thus, in some aspects, theapplication of PUSCH repetition may be linked to a subset of preamblesequences.

In some aspects, a format of a preamble of the random access message mayindicate whether PUSCH repetition was applied when transmitting therandom access message. Thus, in some aspects, the application of PUSCHrepetition may be linked to the format of the preamble.

In some aspects, a format of a preamble of the random access messageindicates an MCS for the PUSCH included in the random access message.Thus, in some aspects, the application of different MCSs for PUSCH maybe linked to the format of the preamble.

In some aspects, preamble repetition of the random access message mayindicate whether PUSCH repetition was applied when transmitting therandom access message. Thus, in some aspects, the application of PUSCHrepetition may be linked to preamble repetition.

In some aspects, a length of a preamble of the random access message mayindicate whether PUSCH repetition was applied when transmitting therandom access message. Thus, in some aspects, the application of PUSCHrepetition may be linked to the length of the preamble.

In some aspects, a resource allocation of a PUSCH occasion and aselection of a PUSCH resource unit, relative to a RACH occasion, may bebased at least in part on whether the signal strength satisfies thethreshold TH1. That is, in some aspects, a resource allocation of aPUSCH occasion and a selection of a PUSCH resource unit, relative to aRACH occasion, may differ depending on the message type. In someaspects, information associated with the resource allocation of thePUSCH occasion and the selection of the PUSCH resource unit, relative tothe RACH occasion, may be identified in the system information receivedby the UE.

As shown by reference 325, the base station may receive (e.g., usingreceive processor 238, controller/processor 240, memory 242, receptioncomponent 804, and/or the like) the random access message associatedwith the two-step RACH procedure. The base station may then determine(e.g., using receive processor 238, controller/processor 240, memory242, determination component 806, and/or the like) the message type ofthe random access message. For example, the base station may determinethe message type based at least in part on the format of the preamble(e.g., when the format of the preamble is a format associated with agiven message type). As another example, the base station may determinethe message type based at least in part on a preamble sequence of therandom access message (e.g., when the preamble sequence is one of a setof preamble sequences associated with a given message type). As anotherexample, the base station may determine the message type based at leastin part on a length of a preamble of the random access message (e.g.,when the length of the preamble is associated with a given messagetype). As another example, the base station may determine the messagetype based at least in part on whether preamble repetition was appliedfor the random access message (e.g., when application of preamblerepetition is indicative of a given message type). As another example,the base station may determine the message type based at least in parton a set of resources in which the random access message is received(e.g., when a set of resources in which random access messages arecommunicated is dependent on message type).

As shown by reference 330, the base station may process (e.g., usingtransmit processor 220, receive processor 238, controller/processor 240,memory 242, processing component 808, and/or the like) the random accessmessage based at least in part on determining the message type of therandom access message. For example, after determining the message type,the base station may determine a configuration of the random accessmessage that identifies one or more characteristics of the message type(e.g., PRACH format, PUSCH repetition, MCS, payload size, PUSCH resourceallocation), and may decode the random access message according to theconfiguration. After decoding the random access message, the basestation may then proceed with the two-step RACH procedure (e.g., bypreparing and transmitting msgB).

As indicated above, FIG. 3 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 3.

FIG. 4 is a diagram illustrating an example process 400 performed, forexample, by a UE, in accordance with various aspects of the presentdisclosure. Example process 400 is an example where the UE (e.g., UE 120and/or the like) performs operations associated with selection of amessage type for a random access message in a two-step RACH procedure.

As shown in FIG. 4, in some aspects, process 400 may include determininga message type for a random access message associated with a two-stepRACH procedure (block 410). For example, the UE (e.g., using receiveprocessor 258, transmit processor 264, controller/processor 280, memory282, and/or the like) may determine a message type for a random accessmessage associated with a two-step RACH procedure (e.g., as describedabove in association with reference 315 of FIG. 3). In some aspects, themessage type is either a first message type or a second message type,the first message type being different from the second message type. Insome aspects, the message type is determined based at least in part onwhether a signal strength satisfies a signal strength threshold.

As further shown in FIG. 4, in some aspects, process 400 may includetransmitting the random access message based at least in part on thedetermined message type (block 420). For example, the UE (e.g., usingtransmit processor 264, controller/processor 280, memory 282, and/or thelike) may transmit the random access message based at least in part onthe determined message type (e.g., as described above in associationwith reference 320 of FIG. 3).

Process 400 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more other processes described elsewhere herein.

In a first aspect, the message type is determined to be the firstmessage type when the signal strength satisfies the signal strengththreshold, and is determined to be the second message type when thesignal strength does not satisfy the signal strength threshold.

In a second aspect, alone or in combination with the first aspect, thefirst message type includes a message type of a first message in thetwo-step RACH procedure and the second message type includes a coverageenhanced message type of the first message in the two-step RACHprocedure.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the signal strength threshold is identified insystem information received by the UE from a base station.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, the system information is carried byremaining minimum system information.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, a PRACH format associated with the first messagetype is different from a PRACH format associated with the second messagetype.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, PUSCH repetition is not to be applied for thefirst message type, and PUSCH repetition is to be applied for the secondmessage type.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, an MCS associated with the first messagetype is different from an MCS associated with the second message type.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, a payload size associated with the firstmessage type is different from a payload size associated with the secondmessage type.

In a ninth aspect, alone or in combination with one or more of the firstthrough eighth aspects, a PUSCH resource allocation associated with thefirst message type is different from a PUSCH resource allocation sizeassociated with the second message type.

In a tenth aspect, alone or in combination with one or more of the firstthrough ninth aspects, a preamble sequence included in the random accessmessage indicates whether PUSCH repetition was applied when transmittingthe random access message, the preamble sequence being one of a set ofpreamble sequences associated with indicating application of PUSCHrepetition.

In an eleventh aspect, alone or in combination with one or more of thefirst through tenth aspects, a format of a preamble of the random accessmessage indicates whether physical uplink shared channel repetition wasapplied when transmitting the random access message.

In a twelfth aspect, alone or in combination with one or more of thefirst through eleventh aspects, a format of a preamble of the randomaccess message indicates a modulation and coding scheme for a physicaluplink shared channel included in the random access message.

In a thirteenth aspect, alone or in combination with one or more of thefirst through twelfth aspects, a resource allocation of a PUSCH occasionand a selection of a PUSCH resource unit, relative to a RACH occasion,is based at least in part on whether the signal strength satisfies thesignal strength threshold.

In a fourteenth aspect, alone or in combination with one or more of thefirst through thirteenth aspects, information associated with theresource allocation of the PUSCH occasion and the selection of the PUSCHresource unit, relative to the RACH occasion, is identified in systeminformation received by the UE.

In a fifteenth aspect, alone or in combination with one or more of thefirst through fourteenth aspects, process 400 includes receiving an SSB,and determining the signal strength based at least in part on areference signal received power associated with the SSB.

In a sixteenth aspect, alone or in combination with one or more of thefirst through fifteenth aspects, process 400 includes receivingconfiguration information associated with the second message type, theconfiguration information including information associated with at leastone of: a PRACH format; application of PUSCH repetition; an MCS; apayload size; a resource allocation for PUSCH, application of preamblerepetition; or a preamble length.

In a seventeenth aspect, alone or in combination with one or more of thefirst through sixteenth aspects, the configuration information isreceived in at least one of: an SSB; system information; a PDCCH; orRMSI.

In an eighteenth aspect, alone or in combination with one or more of thefirst through seventeenth aspects, process 400 includes determining,based at least in part on another signal strength threshold, that thetwo-step RACH procedure is to be used in association with accessing awireless communication system.

In a nineteenth aspect, alone or in combination with one or more of thefirst through eighteenth aspects, the random access message is msgA.

In a twentieth aspect, alone or in combination with one or more of thefirst through nineteenth aspects, preamble repetition is not to beapplied for the first message type, and preamble repetition is to beapplied for the second message type.

In a twenty-first aspect, alone or in combination with one or more ofthe first through twentieth aspects, a preamble length associated withthe first message type is different from a preamble length associatedwith the second message type

Although FIG. 4 shows example blocks of process 400, in some aspects,process 400 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 4.Additionally, or alternatively, two or more of the blocks of process 400may be performed in parallel.

FIG. 5 is a diagram illustrating an example process 500 performed, forexample, by a base station, in accordance with various aspects of thepresent disclosure. Example process 500 is an example where the basestation (e.g., base station 110 and/or the like) performs operationsassociated with selection of a message type for a random access messagein a two-step RACH procedure.

As shown in FIG. 5, in some aspects, process 500 may include receiving,from a UE, a random access message associated with a two-step RACHprocedure (block 510). For example, the base station (e.g., usingtransmit processor 220, controller/processor 240, memory 242, and/or thelike) may receive, from a UE (e.g., UE 120), a random access messageassociated with a two-step RACH procedure (e.g., as described above inassociation with reference 325 of FIG. 3).

As further shown in FIG. 5, in some aspects, process 500 may includedetermining, based at least in part on the random access message, amessage type of the random access message (block 520). For example, thebase station (e.g., using transmit processor 220, receive processor 238,controller/processor 240, memory 242, and/or the like) may determine,based at least in part on the random access message, a message type ofthe random access message (e.g., as described above in association withreference 325 of FIG. 3). In some aspects, the message type is either afirst message type or a second message type, the first message typebeing different from the second message type.

As further shown in FIG. 5, in some aspects, process 500 may includeprocessing the random access message based at least in part ondetermining the message type of the random access message (block 530).For example, the base station (e.g., using transmit processor 220,receive processor 238, controller/processor 240, memory 242, and/or thelike) may process the random access message based at least in part ondetermining the message type of the random access message (e.g., asdescribed above in association with reference 330 of FIG. 3).

Process 500 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more other processes described elsewhere herein.

In a first aspect, the first message type includes a message type of afirst message in the two-step RACH procedure and the second message typeincludes a coverage enhanced message type of the first message in thetwo-step RACH procedure.

In a second aspect, alone or in combination with the first aspect, asignal strength threshold, associated with determining to use the secondmessage type, is identified in system information transmitted by thebase station.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the system information is carried by remainingminimum system information.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, a PRACH format associated with the firstmessage type is different from a PRACH format associated with the secondmessage type.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, PUSCH repetition is not to be applied for thefirst message type and PUSCH repetition is to be applied for the secondmessage type.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, an MCS associated with the first message type isdifferent from an MCS associated with the second message type.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, a payload size associated with the firstmessage type is different from a payload size associated with the secondmessage type.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, a PUSCH resource allocation associatedwith the first message type is different from a PUSCH resourceallocation size associated with the second message type.

In a ninth aspect, alone or in combination with one or more of the firstthrough eighth aspects, a preamble sequence included in the randomaccess message indicates whether PUSCH repetition was applied whentransmitting the random access message, the preamble sequence being oneof a set of preamble sequences associated with indicating application ofPUSCH repetition.

In a tenth aspect, alone or in combination with one or more of the firstthrough ninth aspects, a format of a preamble of the random accessmessage indicates whether physical uplink shared channel repetition wasapplied when transmitting the random access message.

In an eleventh aspect, alone or in combination with one or more of thefirst through tenth aspects, a format of a preamble of the random accessmessage indicates a modulation and coding scheme for a physical uplinkshared channel included in the random access message.

In a twelfth aspect, alone or in combination with one or more of thefirst through eleventh aspects, a resource allocation of a PUSCHoccasion and a selection of a PUSCH resource unit, relative to a RACHoccasion, is based at least in part on whether a signal strengthsatisfies a signal strength threshold.

In a thirteenth aspect, alone or in combination with one or more of thefirst through twelfth aspects, information associated with the resourceallocation of the PUSCH occasion and the selection of the PUSCH resourceunit, relative to the RACH occasion, is identified in system informationtransmitted by the base station.

In a fourteenth aspect, alone or in combination with one or more of thefirst through thirteenth aspects, process 500 includes transmitting anSSB to enable a determination of a signal strength based at least inpart on a reference signal received power associated with the SSB.

In a fifteenth aspect, alone or in combination with one or more of thefirst through fourteenth aspects, process 500 includes transmittingconfiguration information associated with the second message type, theconfiguration information including information associated with at leastone of: a PRACH format; application of PUSCH repetition; an MCS; apayload size; a resource allocation for PUSCH, application of preamblerepetition; or a preamble length.

In a sixteenth aspect, alone or in combination with one or more of thefirst through fifteenth aspects, the configuration information istransmitted in at least one of: an SS; system information; a PDCCH; orRMSI.

In a seventeenth aspect, alone or in combination with one or more of thefirst through sixteenth aspects, the random access message is msgA.

In an eighteenth aspect, alone or in combination with one or more of thefirst through seventeenth aspects, preamble repetition is not to beapplied for the first message type, and preamble repetition is to beapplied for the second message type.

In a nineteenth aspect, alone or in combination with one or more of thefirst through eighteenth aspects, a preamble length associated with thefirst message type is different from a preamble length associated withthe second message type

Although FIG. 5 shows example blocks of process 500, in some aspects,process 500 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 5.Additionally, or alternatively, two or more of the blocks of process 500may be performed in parallel.

FIG. 6 is a conceptual data flow diagram 600 illustrating a data flowbetween different components in an example apparatus 602. The apparatus602 may be a UE (e.g., UE 120). In some aspects, the apparatus 602includes a reception component 604, a determination component 606,and/or a transmission component 608.

In some aspects, one or more components of apparatus 602 may operate toperform one or more operations described herein. For example, receptioncomponent 604 may operate to receive an SSB transmitted by a basestation (e.g., base station 110). Determination component 606 mayoperate to determine a signal strength based at least in part on an RSRPassociated with the SSB, and determine a message type for a randomaccess message associated with a two-step RACH procedure based at leastin part on whether a signal strength satisfies a signal strengththreshold. Transmission component 608 may operate to transmit (e.g., tobase station 650) the random access message based at least in part onthe determined message type.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned process 400 of FIG. 4and/or the like. Each block in the aforementioned process 400 of FIG. 4and/or the like may be performed by a component and the apparatus mayinclude one or more of those components. The components may be one ormore hardware components specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

The number and arrangement of components shown in FIG. 6 are provided asan example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 6. Furthermore, two or more components shown inFIG. 6 may be implemented within a single component, or a singlecomponent shown in FIG. 6 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of components (e.g.,one or more components) shown in FIG. 6 may perform one or morefunctions described as being performed by another set of componentsshown in FIG. 6.

FIG. 7 is a diagram 700 illustrating an example of a hardwareimplementation for an apparatus 602′ employing a processing system 702.The apparatus 602′ may be a UE (e.g., a UE 120).

The processing system 702 may be implemented with a bus architecture,represented generally by the bus 704. The bus 704 may include any numberof interconnecting buses and bridges depending on the specificapplication of the processing system 702 and the overall designconstraints. The bus 704 links together various circuits including oneor more processors and/or hardware components, represented by theprocessor 706, the components 604, 606, 608, and the computer-readablemedium/memory 708. The bus 704 may also link various other circuits suchas timing sources, peripherals, voltage regulators, and power managementcircuits, which are well known in the art, and therefore will not bedescribed any further.

The processing system 702 may be coupled to a transceiver 710. Thetransceiver 710 is coupled to one or more antennas 712. The transceiver710 provides a means for communicating with various other apparatusesover a transmission medium. The transceiver 710 receives a signal fromthe one or more antennas 712, extracts information from the receivedsignal, and provides the extracted information to the processing system702, specifically the reception component 604. In addition, thetransceiver 710 receives information from the processing system 702,specifically the transmission component 608, and based at least in parton the received information, generates a signal to be applied to the oneor more antennas 712. The processing system 702 includes a processor 706coupled to a computer-readable medium/memory 708. The processor 706 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 708. The software, whenexecuted by the processor 706, causes the processing system 702 toperform the various functions described herein for any particularapparatus. The computer-readable medium/memory 708 may also be used forstoring data that is manipulated by the processor 706 when executingsoftware. The processing system further includes at least one of thecomponents 604, 606, and 608. The components may be software modulesrunning in the processor 706, resident/stored in the computer readablemedium/memory 708, one or more hardware modules coupled to the processor706, or some combination thereof. The processing system 702 may be acomponent of the UE 120 and may include the memory 282 and/or at leastone of the TX MIMO processor 266, the RX processor 258, and/or thecontroller/processor 280.

In some aspects, the apparatus 602/602′ for wireless communicationincludes means for determining a message type for a random accessmessage associated with a two-step RACH procedure, wherein the messagetype is either a first message type or a second message type, the firstmessage type being different from the second message type, and whereinthe message type is determined based at least in part on whether asignal strength satisfies a signal strength threshold; means fortransmitting the random access message based at least in part on thedetermined message type; and/or the like. The aforementioned means maybe one or more of the aforementioned components of the apparatus 602and/or the processing system 702 of the apparatus 602′ configured toperform the functions recited by the aforementioned means. As describedelsewhere herein, the processing system 702 may include the TX MIMOprocessor 266, the RX processor 258, and/or the controller/processor280. In one configuration, the aforementioned means may be the TX MIMOprocessor 266, the RX processor 258, and/or the controller/processor 280configured to perform the functions and/or operations recited herein.

FIG. 7 is provided as an example. Other examples may differ from what isdescribed in connection with FIG. 7.

FIG. 8 is a conceptual data flow diagram 800 illustrating a data flowbetween different components in an example apparatus 802. The apparatus802 may be a base station (e.g., base station 110). In some aspects, theapparatus 802 includes a reception component 804, a determinationcomponent 806, a processing component 808, and/or a transmissioncomponent 810.

In some aspects, one or more components of apparatus 802 may operate toperform one or more operations described herein. For example, receptioncomponent 804 may operate to receive (e.g., from a UE 850) a randomaccess message, associated with a two-step RACH procedure. Determinationcomponent 806 may determine, based at least in part on the random accessmessage, a message type of the random access message. Processingcomponent 808 may process the random access message based at least inpart on determining the message type of the random access message.Transmission component 810 may transmit (e.g., to the UE 850) a randomaccess response (e.g., msgB) associated with the random access message.

The apparatus may include additional components that perform each of theblocks of the algorithm in the aforementioned process 500 of FIG. 5and/or the like. Each block in the aforementioned process 500 of FIG. 5and/or the like may be performed by a component and the apparatus mayinclude one or more of those components. The components may be one ormore hardware components specifically configured to carry out the statedprocesses/algorithm, implemented by a processor configured to performthe stated processes/algorithm, stored within a computer-readable mediumfor implementation by a processor, or some combination thereof.

The number and arrangement of components shown in FIG. 8 are provided asan example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 8. Furthermore, two or more components shown inFIG. 8 may be implemented within a single component, or a singlecomponent shown in FIG. 8 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of components (e.g.,one or more components) shown in FIG. 8 may perform one or morefunctions described as being performed by another set of componentsshown in FIG. 8.

FIG. 9 is a diagram 900 illustrating an example of a hardwareimplementation for an apparatus 802′ employing a processing system 902.The apparatus 802′ may be a base station (e.g., base station 110).

The processing system 902 may be implemented with a bus architecture,represented generally by the bus 904. The bus 904 may include any numberof interconnecting buses and bridges depending on the specificapplication of the processing system 902 and the overall designconstraints. The bus 904 links together various circuits including oneor more processors and/or hardware components, represented by theprocessor 906, the components 804, 806, 808, 810 and thecomputer-readable medium/memory 908. The bus 904 may also link variousother circuits such as timing sources, peripherals, voltage regulators,and power management circuits, which are well known in the art, andtherefore will not be described any further.

The processing system 902 may be coupled to a transceiver 910. Thetransceiver 910 is coupled to one or more antennas 912. The transceiver910 provides a means for communicating with various other apparatusesover a transmission medium. The transceiver 910 receives a signal fromthe one or more antennas 912, extracts information from the receivedsignal, and provides the extracted information to the processing system902, specifically the reception component 804. In addition, thetransceiver 910 receives information from the processing system 902,specifically the transmission component 810, and based at least in parton the received information, generates a signal to be applied to the oneor more antennas 912. The processing system 902 includes a processor 906coupled to a computer-readable medium/memory 908. The processor 906 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 908. The software, whenexecuted by the processor 906, causes the processing system 902 toperform the various functions described herein for any particularapparatus. The computer-readable medium/memory 908 may also be used forstoring data that is manipulated by the processor 906 when executingsoftware. The processing system further includes at least one of thecomponents 804, 806, 808, and 810. The components may be softwaremodules running in the processor 906, resident/stored in the computerreadable medium/memory 908, one or more hardware modules coupled to theprocessor 906, or some combination thereof. The processing system 902may be a component of the base station 110 and may include the memory242 and/or at least one of the TX MIMO processor 230, the RX processor238, and/or the controller/processor 240.

In some aspects, the apparatus 802/802′ for wireless communicationincludes means for receiving, from a UE 120, a random access messageassociated with a two-step RACH procedure; means for determining, basedat least in part on the random access message, a message type of therandom access message, wherein the message type is either a firstmessage type or a second message type, the first message type beingdifferent from the second message type; means for processing the randomaccess message based at least in part on determining the message type ofthe random access message; and/or the like. The aforementioned means maybe one or more of the aforementioned components of the apparatus 802and/or the processing system 902 of the apparatus 802′ configured toperform the functions recited by the aforementioned means. As describedelsewhere herein, the processing system 902 may include the TX MIMOprocessor 230, the receive processor 238, and/or thecontroller/processor 240. In one configuration, the aforementioned meansmay be the TX MIMO processor 230, the receive processor 238, and/or thecontroller/processor 240 configured to perform the functions and/oroperations recited herein.

FIG. 9 is provided as an example. Other examples may differ from what isdescribed in connection with FIG. 9.

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method of wireless communication performed by a userequipment (UE), comprising: determining a message type for a randomaccess message associated with a two-step random access channel (RACH)procedure, wherein the message type is either a first message type or asecond message type, the first message type being different from thesecond message type, and wherein the message type is determined based atleast in part on whether a signal strength satisfies a signal strengththreshold; and transmitting the random access message based at least inpart on the determined message type.

Aspect 2: The method of aspect 1, wherein the message type is determinedto be the first message type when the signal strength satisfies thesignal strength threshold, and is determined to be the second messagetype when the signal strength does not satisfy the signal strengththreshold.

Aspect 3: The method of any of aspects 1-2, wherein the first messagetype includes a message type of a first message in the two-step RACHprocedure and the second message type includes a coverage enhancedmessage type of the first message in the two-step RACH procedure.

Aspect 4: The method of any of aspects 1-3, wherein the random accessmessage is msgA.

Aspect 5: The method of any of aspects 1-4, further comprising receivingsystem information from the base station, wherein the signal strengththreshold is identified in the system information received by the UE.

Aspect 6: The method of any of aspects 1-5, further comprising receivingthe signal strength threshold in system information comprising remainingminimum system information.

Aspect 7: The method of any of aspects 1-6, wherein transmitting therandom access message comprises transmitting with a physical randomaccess channel (PRACH) format, wherein the PRACH format when the firstmessage type is determined is different from the PRACH format when thesecond message type is determined.

Aspect 8: The method of any of aspects 1-7, wherein transmitting therandom access message comprises applying physical uplink shared channel(PUSCH) repetition if the first message type is determined and notapplying PUSCH repetition if the second message type is determined.

Aspect 9: The method of any of aspects 1-8, wherein transmitting therandom access message comprises transmitting with a modulation andcoding scheme (MCS), wherein the MCS when the first message type isdetermined is different from the MCS when the second message type isdetermined.

Aspect 10: The method of any of aspects 1-9, wherein transmitting therandom access message comprises transmitting with a payload size,wherein the payload size when the first message type is determined isdifferent from the payload size when the second message type isdetermined.

Aspect 11: The method of any of aspects 1-10, wherein transmitting therandom access message comprises transmitting with a physical uplinkshared channel (PUSCH) resource allocation, wherein the PUSCH resourceallocation when the first message type is determined is different fromthe PUSCH resource allocation when the second message type isdetermined.

Aspect 12: The method of any of aspects 1-11, wherein transmitting therandom access message comprises applying preamble repetition if thefirst message type is determined and not applying preamble repetition ifthe second message type is determined.

Aspect 13: The method of any of aspects 1-12, wherein transmitting therandom access message comprises transmitting with a preamble length,wherein the preamble length when the first message type is determined isdifferent from the preamble length when the second message type isdetermined.

Aspect 14: The method of any of aspects 1-13, wherein transmitting therandom access message comprises transmitting using a preamble sequence,wherein the preamble sequence indicates whether physical uplink sharedchannel (PUSCH) repetition was applied when transmitting the randomaccess message, the preamble sequence being one of a set of preamblesequences associated with indicating application of PUSCH repetition.

Aspect 15: The method of any of aspects 1-14 wherein transmitting therandom access message comprises transmitting with a format of a preamblethat indicates whether physical uplink shared channel repetition wasapplied when transmitting the random access message.

Aspect 16: The method of any of aspects 1-15, wherein transmitting therandom access message comprises transmitting with a format of a preamblethat indicates a modulation and coding scheme for a physical uplinkshared channel included in the random access message.

Aspect 17: The method of any of aspects 1-16, further comprisingdetermining whether the signal strength satisfies the signal strengththreshold, wherein a resource allocation of a physical uplink sharedchannel (PUSCH) occasion and a selection of a PUSCH resource unit,relative to a RACH occasion, is based at least in part on thedetermination of whether the signal strength satisfies the signalstrength threshold.

Aspect 18: The method of aspect 17, further comprising receiving systeminformation that identifies information associated with the resourceallocation of the PUSCH occasion and the selection of the PUSCH resourceunit relative to the RACH occasion.

Aspect 19: The method of any of aspects 1-18, further comprising:receiving a synchronization signal block (SSB); and determining thesignal strength based at least in part on a reference signal receivedpower associated with the SSB.

Aspect 20: The method of any of aspects 1-19, further comprising:receiving configuration information associated with the second messagetype, the configuration information including information associatedwith at least one of: a physical random access channel (PRACH) format;application of physical uplink shared channel (PUSCH) repetition; amodulation and coding scheme; a payload size; a resource allocation forPUSCH; application of preamble repetition; or a preamble length.

Aspect 21: The method of aspect 20, further comprising receiving theconfiguration information in at least one of: a synchronization signalblock; system information; a physical downlink control channel; orremaining minimum system information.

Aspect 22: The method of any of aspects 1-21, further comprising:determining, based at least in part on another signal strengththreshold, that the two-step RACH procedure is to be used in associationwith accessing a wireless communication system.

Aspect 23: A method of wireless communication performed by a basestation, comprising: receiving, from a user equipment (UE), a randomaccess message associated with a two-step random access channel (RACH)procedure; determining, based at least in part on the random accessmessage, a message type of the random access message, wherein themessage type is either a first message type or a second message type,the first message type being different from the second message type; andprocessing the random access message based at least in part ondetermining the message type of the random access message.

Aspect 24: The method of aspect 23, wherein the first message typeincludes a message type of a first message in the two-step RACHprocedure and the second message type includes a coverage enhancedmessage type of the first message in the two-step RACH procedure.

Aspect 25: The method of any of aspects 23-24, further comprisingtransmitting system information that identifies a signal strengththreshold associated with determining to use the second message type.

Aspect 26: The method of any of aspects 23-25, further comprisingtransmitting the signal strength threshold in system informationcomprising remaining minimum system information.

Aspect 27: The method of any of aspects 23-26, wherein processing therandom access message comprises processing based on a physical randomaccess channel (PRACH) format, wherein the PRACH format when the firstmessage type is determined is different from the PRACH format when thesecond message type is determined.

Aspect 28: The method of any of aspects 23-27, wherein processing therandom access message comprises processing based on a determination ofwhether physical uplink shared channel (PUSCH) repetition is applied,wherein PUSCH repetition is determined not to be applied if the firstmessage type is determined and PUSCH repetition is determined to beapplied if the second message type is determined.

Aspect 29: The method of any of aspects 23-28, wherein processing therandom access message comprises processing based on a modulation andcoding scheme (MCS), wherein the MCS when the first message type isdetermined is different from the MCS when the second message type isdetermined.

Aspect 30: The method of any of aspects 23-29, wherein processing therandom access message comprises processing based on a payload size,wherein the payload size when the first message type is determined isdifferent from the payload size when the second message type isdetermined.

Aspect 31: The method of any of aspects 23-30, wherein processing therandom access message comprises processing based on a PUSCH resourceallocation, wherein the PUSCH resource allocation when the first messagetype is determined is different from the PUSCH resource allocation whenthe second message type is determined.

Aspect 32: The method of any of aspects 23-31, wherein processing therandom access message comprises processing based on a determination ofwhether preamble repetition is applied, wherein preamble repetition isdetermined not to be applied if the first message type is determined andpreamble repetition is determined to be applied if the second messagetype is determined.

Aspect 33: The method of any of aspects 23-32, wherein processing therandom access message comprises processing based on a preamble length,wherein the preamble length when the first message type is determined isdifferent from the preamble length when the second message type isdetermined.

Aspect 34: The method of any of aspects 23-33, wherein receiving therandom access message comprises receiving an indication of whetherphysical uplink shared channel (PUSCH) repetition was applied whentransmitting the random access message, wherein the indication is apreamble sequence included in the random access message, the preamblesequence being one of a set of preamble sequences associated withindicating application of PUSCH repetition.

Aspect 35: The method of any of aspects 23-34, wherein receiving therandom access message comprises receiving an indication of whetherphysical uplink shared channel (PUSCH) repetition was applied whentransmitting the random access message, wherein the indication is aformat of a preamble of the random access message.

Aspect 36: The method of any of aspects 23-35, wherein receiving therandom access message comprises receiving an indication of a modulationand coding scheme (MCS) for a physical uplink shard channel included inthe random access message, wherein the indication is a format of apreamble of the random access message.

Aspect 37: The method of any of aspects 23-36, wherein a resourceallocation of a physical uplink shared channel (PUSCH) occasion and aselection of a PUSCH resource unit, relative to a RACH occasion, isbased at least in part on whether a signal strength satisfies a signalstrength threshold.

Aspect 38: The method of aspect 37, further comprising transmittingsystem information that identifies information associated with theresource allocation of the PUSCH occasion and the selection of the PUSCHresource unit relative to the RACH occasion.

Aspect 39: The method of any of aspects 23-38, further comprising:transmitting a synchronization signal block (SSB) to enable adetermination of a signal strength based at least in part on of areference signal received power associated with the SSB.

Aspect 40: The method of any of aspects 23-39, further comprising:transmitting configuration information associated with the secondmessage type, the configuration information including informationassociated with at least one of: a physical random access channel(PRACH) format; application of physical uplink shared channel (PUSCH)repetition; a modulation and coding scheme; a payload size; a resourceallocation for PUSCH; application of preamble repetition; or a preamblelength.

Aspect 41: The method of any of aspects 23-40, further comprisingtransmitting the configuration information in at least one of: asynchronization signal block; system information; a physical downlinkcontrol channel; or remaining minimum system information.

Aspect 42: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more aspects ofaspects 1-22.

Aspect 43: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more aspectsof aspects 1-22.

Aspect 44: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more aspects of aspects1-22.

Aspect 45: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more aspects of aspects 1-22.

Aspect 46: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore aspects of aspects 1-22.

Aspect 47: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more aspects ofaspects 23-41.

Aspect 48: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more aspectsof aspects 23-41.

Aspect 49: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more aspects of aspects23-41.

Aspect 50: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more aspects of aspects 23-41.

Aspect 51: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore aspects of aspects 23-41.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseform disclosed. Modifications and variations may be made in light of theabove disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construedas hardware, firmware, and/or a combination of hardware and software. Asused herein, a processor is implemented in hardware, firmware, and/or acombination of hardware and software.

As used herein, satisfying a threshold may, depending on the context,refer to a value being greater than the threshold, greater than or equalto the threshold, less than the threshold, less than or equal to thethreshold, equal to the threshold, not equal to the threshold, and/orthe like.

It will be apparent that systems and/or methods described herein may beimplemented in different forms of hardware, firmware, and/or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the aspects. Thus, the operation and behavior of thesystems and/or methods were described herein without reference tospecific software code—it being understood that software and hardwarecan be designed to implement the systems and/or methods based, at leastin part, on the description herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof various aspects includes each dependent claim in combination withevery other claim in the claim set. A phrase referring to “at least oneof” a list of items refers to any combination of those items, includingsingle members. As an example, “at least one of: a, b, or c” is intendedto cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combinationwith multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c,a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering ofa, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the terms “set” and “group” are intended to include oneor more items (e.g., related items, unrelated items, a combination ofrelated and unrelated items, and/or the like), and may be usedinterchangeably with “one or more.” Where only one item is intended, thephrase “only one” or similar language is used. Also, as used herein, theterms “has,” “have,” “having,” and/or the like are intended to beopen-ended terms. Further, the phrase “based on” is intended to mean“based, at least in part, on” unless explicitly stated otherwise.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), comprising: determining a message type for a randomaccess message associated with a two-step random access channel (RACH)procedure, wherein the message type is either a first message type or asecond message type, the first message type being different from thesecond message type, and wherein the message type is determined based atleast in part on whether a signal strength satisfies a signal strengththreshold; and transmitting the random access message based at least inpart on the determined message type.
 2. The method of claim 1, whereinthe message type is determined to be the first message type when thesignal strength satisfies the signal strength threshold, and isdetermined to be the second message type when the signal strength doesnot satisfy the signal strength threshold.
 3. The method of claim 1,wherein the first message type includes a message type of a firstmessage in the two-step RACH procedure and the second message typeincludes a coverage enhanced message type of the first message in thetwo-step RACH procedure.
 4. The method of claim 1, wherein the randomaccess message is msgA.
 5. The method of claim 1, further comprisingreceiving system information from the base station, wherein the signalstrength threshold is identified in the system information received bythe UE.
 6. The method of claim 1, further comprising receiving thesignal strength threshold in system information comprising remainingminimum system information.
 7. The method of claim 1, whereintransmitting the random access message comprises transmitting with aphysical random access channel (PRACH) format, wherein the PRACH formatwhen the first message type is determined is different from the PRACHformat when the second message type is determined.
 8. The method ofclaim 1, wherein transmitting the random access message comprisesapplying physical uplink shared channel (PUSCH) repetition if the firstmessage type is determined and not applying PUSCH repetition if thesecond message type is determined.
 9. The method of claim 1, whereintransmitting the random access message comprises transmitting with amodulation and coding scheme (MCS), wherein the MCS when the firstmessage type is determined is different from the MCS when the secondmessage type is determined.
 10. The method of claim 1, whereintransmitting the random access message comprises transmitting with apayload size, wherein the payload size when the first message type isdetermined is different from the payload size when the second messagetype is determined.
 11. The method of claim 1, wherein transmitting therandom access message comprises transmitting with a physical uplinkshared channel (PUSCH) resource allocation, wherein the PUSCH resourceallocation when the first message type is determined is different fromthe PUSCH resource allocation when the second message type isdetermined.
 12. The method of claim 1, wherein transmitting the randomaccess message comprises applying preamble repetition if the firstmessage type is determined and not applying preamble repetition if thesecond message type is determined.
 13. The method of claim 1, whereintransmitting the random access message comprises transmitting with apreamble length, wherein the preamble length when the first message typeis determined is different from the preamble length when the secondmessage type is determined.
 14. The method of claim 1, whereintransmitting the random access message comprises transmitting using apreamble sequence, wherein the preamble sequence indicates whetherphysical uplink shared channel (PUSCH) repetition was applied whentransmitting the random access message, the preamble sequence being oneof a set of preamble sequences associated with indicating application ofPUSCH repetition.
 15. The method of claim 1, wherein transmitting therandom access message comprises transmitting with a format of a preamblethat indicates whether physical uplink shared channel repetition wasapplied when transmitting the random access message.
 16. The method ofclaim 1, wherein transmitting the random access message comprisestransmitting with a format of a preamble that indicates a modulation andcoding scheme for a physical uplink shared channel included in therandom access message.
 17. The method of claim 1, further comprisingdetermining whether the signal strength satisfies the signal strengththreshold, wherein a resource allocation of a physical uplink sharedchannel (PUSCH) occasion and a selection of a PUSCH resource unit,relative to a RACH occasion, is based at least in part on thedetermination of whether the signal strength satisfies the signalstrength threshold.
 18. The method of claim 17, further comprisingreceiving system information that identifies information associated withthe resource allocation of the PUSCH occasion and the selection of thePUSCH resource unit relative to the RACH occasion.
 19. The method ofclaim 1, further comprising: receiving a synchronization signal block(SSB); and determining the signal strength based at least in part on areference signal received power associated with the SSB.
 20. The methodof claim 1, further comprising: receiving configuration informationassociated with the second message type, the configuration informationincluding information associated with at least one of: a physical randomaccess channel (PRACH) format; application of physical uplink sharedchannel (PUSCH) repetition; a modulation and coding scheme; a payloadsize; a resource allocation for PUSCH; application of preamblerepetition; or a preamble length.
 21. The method of claim 20, furthercomprising receiving the configuration information in at least one of: asynchronization signal block; system information; a physical downlinkcontrol channel; or remaining minimum system information.
 22. The methodof claim 1, further comprising: determining, based at least in part onanother signal strength threshold, that the two-step RACH procedure isto be used in association with accessing a wireless communicationsystem.
 23. A method of wireless communication performed by a basestation, comprising: receiving, from a user equipment (UE), a randomaccess message associated with a two-step random access channel (RACH)procedure; determining, based at least in part on the random accessmessage, a message type of the random access message, wherein themessage type is either a first message type or a second message type,the first message type being different from the second message type; andprocessing the random access message based at least in part ondetermining the message type of the random access message.
 24. Themethod of claim 23, wherein the first message type includes a messagetype of a first message in the two-step RACH procedure and the secondmessage type includes a coverage enhanced message type of the firstmessage in the two-step RACH procedure.
 25. The method of claim 23,further comprising transmitting system information that identifies asignal strength threshold associated with determining to use the secondmessage type.
 26. The method of claim 23, wherein processing the randomaccess message comprises at least one of: processing based on a physicalrandom access channel (PRACH) format, wherein the PRACH format when thefirst message type is determined is different from the PRACH format whenthe second message type is determined; processing based on adetermination of whether physical uplink shared channel (PUSCH)repetition is applied, wherein PUSCH repetition is determined not to beapplied if the first message type is determined and PUSCH repetition isdetermined to be applied if the second message type is determined;processing based on a modulation and coding scheme (MCS), wherein theMCS when the first message type is determined is different from the MCSwhen the second message type is determined; processing based on apayload size, wherein the payload size when the first message type isdetermined is different from the payload size when the second messagetype is determined; processing based on a PUSCH resource allocation,wherein the PUSCH resource allocation when the first message type isdetermined is different from the PUSCH resource allocation when thesecond message type is determined; processing based on a determinationof whether preamble repetition is applied, wherein preamble repetitionis determined not to be applied if the first message type is determinedand preamble repetition is determined to be applied if the secondmessage type is determined; or processing based on a preamble length,wherein the preamble length when the first message type is determined isdifferent from the preamble length when the second message type isdetermined.
 27. The method of claim 23, wherein receiving the randomaccess message comprises receiving an indication of whether physicaluplink shared channel (PUSCH) repetition was applied when transmittingthe random access message, wherein the indication is at least one of apreamble sequence included in the random access message or a format of apreamble of the random access message, the preamble sequence being oneof a set of preamble sequences associated with indicating application ofPUSCH repetition.
 28. The method of claim 23, wherein receiving therandom access message comprises receiving an indication of a modulationand coding scheme (MCS) for a physical uplink shard channel included inthe random access message, wherein the indication is a format of apreamble of the random access message.
 29. A user equipment (UE) forwireless communication, comprising: a memory; and one or more processorsoperatively coupled to the memory, the memory and the one or moreprocessors configured to: determine a message type for a random accessmessage associated with a two-step random access channel (RACH)procedure, wherein the message type is either a first message type or asecond message type, the first message type being different from thesecond message type, and wherein the message type is determined based atleast in part on whether a signal strength satisfies a signal strengththreshold; and transmit the random access message based at least in parton the determined message type.
 30. A base station for wirelesscommunication, comprising: a memory; and one or more processorsoperatively coupled to the memory, the memory and the one or moreprocessors configured to: receive, from a user equipment (UE), a randomaccess message associated with a two-step random access channel (RACH)procedure; determine, based at least in part on the random accessmessage, a message type of the random access message, wherein themessage type is either a first message type or a second message type,the first message type being different from the second message type; andprocess the random access message based at least in part on determiningthe message type of the random access message.